Certified Rhythm Analysis Technician (CRAT) Practice Exam

Sinus arrest is characterized by a pause in the rhythm where the intrinsic pacing of the heart temporarily stops, leading to a missed heartbeat. The ECG strip showing a regular rhythm with one or more long pauses indicates that a complete cycle has been skipped due to the absence of sinus node depolarization. This results in the visual absence of QRS complexes in the structure of the rhythm.

In this case, a regular rhythm with a long pause specifically points to sinus arrest since it showcases an interruption of the heart's normal pacing mechanism. The rhythm resumes afterwards but does so with a gap, confirming that the sinus node was inactive for that period. This phenomenon is distinctly observed in a regular rhythm pattern, as opposed to patterns that display more irregularities or multiple dropped beats without the clear regularity that indicates a structured sinus arrest.